Also listening to this conversation NPR national political correspondent Mara Liasson. Hey there, Mara.

MARA LIASSON, BYLINE: Hi there, Audie.

CORNISH: So the idea that President Trump wants to crack down on illegal immigration isn't new. Why do you think the focus has come to this issue now?

LIASSON: This is something that the president has talked about a lot. This was one of his signature issues. But this idea of a caravan has been in the news. It's been on Fox. Buzzfeed has been doing a lot on this. And the president is aware of that. He also spent the weekend at Mar-a-Lago with Stephen Miller, his very close aide and the voice for a hard line on immigration inside the White House. He's also been hearing from outside advisers, former campaign aides who are telling him about the unhappiness of his conservative base, particularly about the omnibus spending bill that he signed.

This is the very first time that he's really angered his base. And they don't like what was in the bill, and they don't like what wasn't in the bill. They don't like that the bill only included a couple billion dollars for a border wall, and they don't like that there were other things in the bill that fund Democratic priorities like Planned Parenthood.

So that's maybe the context for why at this moment he started tweeting a lot about this issue. You know, there was a background conference call today with senior administration officials who insisted that the wall was being built, which was interesting. So there he's sending two messages - one, the Democrats aren't giving me money for a wall, but also, the wall is being built.

CORNISH: What did you make of the message from Gidley just now?

LIASSON: I think that he wasn't clear about when the president says a DACA deal is dead what that actually means. I think that if and when DACA kids, who are very sympathetic - the president himself has said he's sympathetic to them - if they start getting deported down the road, I think it will be on the president's lap because he ended this program.

CORNISH: That's NPR's Mara Liasson. Thank you so much for speaking with us.